Pavement repair system utilizing solid phase autoregenerative cohesion

ABSTRACT

A method for repairing asphalt pavement involves passing an emitter over a surface of a damaged asphalt pavement comprising aged asphalt, wherein the emitter comprises a birefringent material through which the electromagnetic radiation generated by the emitter passes, wherein the emitter generates electromagnetic radiation having a wavelength of from about 2 microns to 1 millimeter, the radiation penetrating into the pavement to a depth of at least 2 inches, wherein a temperature differential throughout a top two inches of pavement is 100° F. or less, wherein a highest temperature in the top two inches of pavement does not exceed 300° F., and wherein a minimum temperature in the top two inches of pavement is at least 200° F.

INCORPORATION BY REFERENCE TO RELATED APPLICATIONS

Any and all priority claims identified in the Application Data Sheet, orany correction thereto, are hereby incorporated by reference under 37CFR 1.57. This application is a continuation of U.S. application Ser.No. 14/629,872, filed Feb. 24, 2015, which is a continuation of U.S.application Ser. No. 13/842,640, filed on Mar. 15, 2013, now U.S. Pat.No. 8,992,118. The aforementioned applications are incorporated byreference herein in their entirety, and are hereby expressly made a partof this specification.

FIELD OF THE INVENTION

A pavement repair system is provided utilizing Solid Phase AutoRegenerative Cohesion (SPARC) Homogenization by Liquid AsphaltOligopolymerization (HALO) technologies (“the SPARC-HALO system”). TheSPARC-HALO system is suitable for use in repairing asphalt pavement,including pavement exhibiting a high degree of deterioration (asmanifested in the presence of potholes, cracks, ruts, or the like) aswell as pavement that has been subject to previous repair and maycomprise a substantial amount of dirt and other debris (e.g., chippedroad paint or other damaged or disturbed surfacing materials). The HALOsystem itself is suitable for rejuvenating aged asphalt, therebyimproving properties of the paving material.

BACKGROUND OF THE INVENTION

Repair and maintenance of the civil infrastructure, including roads andhighways of the United States presents great technical and financialchallenges. The American Association of State Highway TransportationOfficials (AASHTO) issued a bottom line report in 2010 stating that $160billion a year must be spent to maintain infrastructure; however, onlyabout $80 billion is being spent. The result is a rapidly failinginfrastructure. New methods of maintaining existing roads and newmethods of constructing roads that would extend the useful life for thesame budget dollar are needed to meet the challenges of addressing ourfailing infrastructure.

In the United States alone there are approximately 4.4 million centerlane miles of asphalt concrete, with a center lane comprising a 24 footwide pavement surface having a lane in each direction. Asphalt concretepaving surfaces are typically prepared by heating aggregate to 400° F.,and applying liquid asphalt (e.g., by spraying into a pug mill or drumcoating) to yield a mixture of 95% aggregate and 5% asphalt. If atemperature of approximately 350° F. is maintained for the mixture, itis considered hot mix asphalt and does not stick to itself as long asthe temperature is maintained. The hot mix asphalt is typically placedin a transfer truck, which hauls it to the job site, where it is placedon either a gravel road base or onto an old road surface that has beenpreviously primed. A paving apparatus receives the hot mix asphalt fromthe transfer truck and spreads it out uniformly across the base surface,and as the material progressively cools below 250° F. degrees it iscompacted with a roller. The hot mix asphalt is rolled to a uniformdensity, and after approximately one to three days of cooling and agingthe surface can be opened to traffic.

After such asphalt pavement has been in place for several years, thepavement progressively ages. Water works its way into the pavement. Itbegins to lose its integrity on the surface, causing aggregate at thesurface of the pavement to be lost. The pavement surface roughens asaggregate is lost, and cracks begin to form. Conventional pavementrepair techniques at this stage in the deterioration process include:pouring hot rubber asphalt into the cracks, using cold patch (apolymer-modified cold mix asphalt that can be applied to a damaged roadsurface, e.g., placed in a pothole, under ambient temperature conditionsusing hand tools). Another technique for repairing pavement exhibitingminimal damage involves application of a liquid asphalt emulsion to thepavement surface so as to provide a degree of waterproofing to slow theaging process, or, for surfaces exhibiting more deterioration,application of a thin layer of a slurry of aggregate and asphaltemulsion over the top of the pavement.

Preparing and installing hot asphalt pavement involves running aggregatethrough a heat tube (typically at around 400° F.) where moisture isdriven off to prevent boil over when the rock contacts molten asphalt.The aggregate is added to asphalt, optionally containing a rubberpolymer. The aggregate is sent through a mill having high velocity tinesthat rolls the aggregate through a spray of asphalt. The resultingmixture of aggregate with baked-on asphalt typically comprises 95%aggregate and 5% asphalt (optionally with rubber polymer). The mixtureexits the mill at about 350° F. and is transported into waiting trucks(e.g., a belly dump truck) which are driven to the job site. Newpavement is laid down over an earthen base covered with gravel that hasbeen graded and compacted. Typically, the new road is not laid in asingle pass. Instead, a first 2-3 inch lift of loose hot asphalt is laiddown and partially compacted, and then a second lift is laid over thefirst and compacted. The temperature of the asphalt concrete pavement atthis stage is typically about 140° F. Additional lifts can be added asdesired, e.g., to a depth of approximately 12 inches, depending upon theexpected usage conditions for the road (heavy or light transportation,the velocity of traffic, desired lifetime). Primer or additionalmaterial is typically not put between layers of lift in newconstruction, as the fresh pavement exhibits good adherence to itself innew construction. New construction design typically never requires anyprimer or additional material between the subsequent lifts.

After approximately fifteen years of exposure to the elements, itbecomes cost prohibitive to attempt to maintain asphalt pavement viaconventional cold patching, waterproofing, and slurry techniques. Theconventional approach at this stage in the deterioration of the pavementtypically involves priming the damages surface and applying a layer ofhot mix asphalt. For pavement too deteriorated for application primingand application of a layer of hot mix asphalt, a cold-in-place recyclingprocess can be employed. In cold-in-place recycling, typically thetopmost 2 to 5 inches of the damaged road surface are pulverized down toa specific aggregate size and mixed with an asphalt emulsion, and thenreinstalled to pave the same road from which the old paving material hasbeen removed.

Existing pavement (asphalt or concrete) is typically repaired by use ofan overlay, e.g., a mixture of aggregate and asphalt such as describedabove for new road construction. In the case of repaving over the top ofrigid concrete, some type of primer is typically applied, e.g., as aspray resulting in application of approximately 10 gallons of primer per1,000 square feet of pavement. The primer can be an asphalt emulsionthat provides a tacky surface for the new overlay. A single layer ofoverlay can be applied, or multiple layers, typically two or more.

Cracks and stresses in a repaired underlying road bed will quicklyimprint themselves on new overlays of paving material, due to themalleability of the new asphalt under rolling loads. As the underlyingroad bed undergoes expansion and contraction under ambient condition,cracks can be telegraphed up through as much as three inches ofoverlying asphalt. A conventional method for achieving some resistanceto the telegraphing of old defects in the underlying road bed is to putdown a hot tack coat of asphalt, lay a polypropylene mat (similar inappearance to spun-bond polypropylene, typically ¼-½ inches inthickness, available as Petromat® from Nilex, Inc. of Centennial, Colo.)over the hot tack coat of asphalt, followed by a layer of new hotasphalt concrete which is then compacted over the existing surface. Thiswill inhibit the rate of telegraphing of cracks to a limited extent,such that instead of taking place from 6 months to 2 years after repair,the cracks do not telegraph for from to 1 year to 3 years after repair.This telegraphing phenomenon by the defects in an existing aged roadbedmanifest surface defects in a new pavement overlay about three timessooner than is common to a fresh asphalt concrete pavement placed on acompacted earthen and gravel base; as is the practice in newconstruction.

Deterioration mechanisms of new highways have been investigated over a20 year life cycle. Overlays are typically applied between the twelfthand fifteenth year. Typically, no significant deterioration is observedover the first five years of a well-built highway. Within the first fiveyears, cracks or potholes typically do not appear unless there is acutedamage to the pavement, or loose material underneath the pavement. Afterthe first five years, physical symptoms of deterioration are observed,including lateral and longitudinal cracks due to shrinkage of thepavement mass through the loss of binder and embrittlement of theasphalt. Cracks ultimately result in creation of a pothole. Ravelling isa mechanism wherein the effects of exposure to water and sun break downthe adhesion between the rock on the top surface of the pavement and theunderlying aggregate, such that small and then larger rock is releasedfrom the pavement. A stress fracture is where the pavement, for onereason or another, may not have been thick enough to withstand exposureto an extremely heavy load, moisture, or poor compaction underneath.When combined with shrinkage of the asphalt itself as it goes throughheating and cooling cycles, and application of oxidative stress, stressfractures can also result. Stress fractures are characterized byextending in different directions (unlike the lateral or longitudinalcracking as described above).

The macro-texture of a pavement refers to the visible roughness of thepavement surface as a whole. The primary function of the macro-textureis to help maintain adequate skid resistance to vehicles travelling athigh speeds. It also provides paths for water to escape which helps toprevent wheels of motor vehicles from hydroplaning. This optionally maybe accomplished through cutting or forming grooves in existing or newpavements. Micro-textures refer to the roughness of the surface of theindividual stones within the asphalt concrete pavement. It is the finetexture that occurs on chippings and other exposed parts of thesurfacing. For concrete pavement this is usually the sand and fineaggregates present at the surface layer and for asphalt it is usuallyassociated with the type of aggregates used. Micro-texture createsfrictional properties for vehicles travelling at low speeds. The wetskid resistant nature of a road is dependent on the interaction of thetire and the combined macro-texture and micro-texture of the roadsurface.

Conventional repair of shallow surface fissures and ravelling usesvarious methods. Re-saturants are materials that soften old asphalt.They are typically mixed with an emulsion and sprayed onto the surfaceof the old pavement. The material penetrates into the uppermost 20 or 30mils of the pavement and softens the asphalt, imparting flexibility.Thermally fluidized hot asphalt can also be sprayed directly onto thesurface, which hardens and provides waterproofing. A fog seal istypically sprayed on the surface, and can be provided with a sandblotter to improve the friction coefficient. In a chip seal, arubberized emulsion can also be sprayed onto the aged pavement, and thenstone is broadcast into the rubberized emulsion which then hardens,bonding the stone. Slurry seal employs a cold aggregate/asphalt mixtureprepared in a pug mill and placed on the aged pavement surface, but isapplied in a much thinner layer, e.g., 0.25-0.75 inches. Once thepavement surface is repaired, any safety markings can be repainted.

The Federal Highway Administration, through the National Academy ofSciences, has done research into pavement durability. A 20-yearlong-term paving program (LTPP) was initiated in 1984 in an attempt tounderstand the failure mechanisms of paving. At the end of the 20-yearprogram and after five years of data analysis, better ways have beendeveloped for measuring pavement failure, the most noteworthy being theStrategic Highway Research Program (SHRP) grading system. The SHRPsystem can be used to determine the physical qualities of an asphaltproduct and its potential for long-term service. Subsequently,mechanical testing was developed to determine when the ductility andflexibility of the pavement was diminished, which correlates with end ofits useful life as well as the chemical changes in the asphalt itselfover time were studied. The presence of carboxylates and sulfoxides thatare generated over the life of the pavement cross-section was discoveredto be associated with asphalt embrittlement. This discovery now enablesprediction of useful life. Accelerated weathering chambers also can beemployed to determine the rate of formation of these telltalecarboxylates and sulfoxides in a new binder system, binder/aggregatecombination, or other paving material thereby predicting an expecteduseful life. In terms of the chemistry of deterioration, study dataindicate that asphalt pavement fails because it becomes brittle.Embrittlement leads to mass loss, which leads to shrinkage, whichproduces cracks. Cracks become potholes, the pavement stops flexing, andaggregate becomes dislodged.

Deterioration of asphalt binder is generally associated with asphaltbeyond the first 100 microns covering the rock surface. An asphalt layeron aggregate at depths within 100 microns of the asphalt/rock interfacewas found by the 20 year LTDP study to have not experienced the presenceof sulfoxides and carboxylates that are associated with embrittlement.Therefore the properties of that asphalt were similar to those of virginasphalt initially placed on the rock. While not wishing to be bound bytheory, it is believed that the tight bond of the asphalt within thefirst 100 microns of the rock surface exhibited a high degree ofintimacy. This intimacy inhibits the movement of scavenging oxidizersinto the asphalt structure, thereby minimizing deterioration.Accordingly, it is believed that in an aged paving material averaging95% aggregate and 5% asphalt, a 100 micron layer of good asphaltsurrounds each aggregate particle, with embrittled asphalt in between.It is this “embrittlement zone” where ductility is lost and failuretakes place. Air gaps in the cross-section of the pavement can allowwater and air to gain access to the asphalt rock interface. Over aperiod of time, the asphalt goes from being flexible to becomingbrittle. The chemistries associated with the embrittlement are relatedto the formation of sulfoxide or hydroxyl groups, and typically there isa loss of a hydrogen atom on the carbon (oxidation) which causes the keymolecular structures to become shorter, thereby less flexible. Once thathappens, the pavement becomes inflexible, cracks open up, the pavementloses mass, and rolling loads break up the pavement, causing cracking,potholes, running, ravelling, and block cracking, each resulting in aloss of the pavement integrity.

The conventional methods for repair of surface defects inclusive ofrejuvenators and fog seals typically do not exhibit a desirablelifespan. The most durable conventional repair, a slurry seal or a chipseal, may last only 7 or 8 years. An analysis of pavement failuremechanisms provides an explanation for the poor lifespan observed fornew asphalt pavement and subsequent repairs. The primary factor is thatthe repairs do not remedy the underlying embrittlement of the asphaltbinder deep within the pavement cross-section. The embrittlement resultsfrom the scissioning of the polymer chains present in the asphalt underthe influence of free radicals associated principally with water. Waterpenetrates the pavement, and sunlight and traffic over the pavementsurface provides energy for reaction with oxygen and other pavementcomponents, yielding sulfoxide and carboxylate reaction products andreduced polymer chain length through reaction with the resulting freeradicals. Loss of polymeric molecular weight impacts the ability of thepavement to stretch and flex. A secondary failure mechanism is loss ofrock itself due to hydrolytic attack of the asphalt-rock interface.Rocks typically comprise metal oxides (e.g., calcium oxide, silicondioxide, lithium oxide, potassium oxide, sodium oxide). Hydroxide groupscan form upon exposure to water, resulting in oxidative reactions thatimpair the adhesion of asphalt to the rock surface, a process referredto as stripping.

Loss of waterproofing typically is a top down mechanism. The asphaltbreaks down from exposure to heavy load and the sun, causing water topenetrate between the asphalt and rock. The asphalt can lose itshydrophobicity, with paraffinic components being broken down into morehydrophilic components, which in turn accelerate the process of wateradsorption. Ravelling occurs, resulting in a loss of macrotexture.Ultimately, the microtexture of the surface is lost due to abrasion oftires across the surface rubbing off the asphalt and polishing the rocksurface, whereby the coefficient of friction drops to unacceptablelevels. Typically, a brand new pavement will have a coefficient offriction of between 0.6 and 0.7. Over time, loss of microtexture andultimately macrotexture results in the coefficient of friction droppingto below about 0.35, at which point the pavement becomes inherentlyunsafe in terms of steer resistance in the presence of water. Even if apavement surface doesn't have ravelling or cracking, it can still beunsafe to drive on due to loss of adequate surface texture. Microtextureand macrotexture mechanisms function at different speeds. Typically, upto about 45 mph the microtexture controls stopping distance. Between 45and 50 the macrotexture begins to have a greater effect on stoppingdistance, and above 50 mph the macrotexture is the principal determiningfactor in stopping distance.

Accordingly, there are a variety of maintenance techniques that can beemployed on damaged asphalt pavement, some of them more successful thanothers in preserving and extending the useful life of the pavement. Itis known that for pavement that is timely and properly maintained, andrepaired in the early stages of deterioration, the typical useful lifecan be extended out to 19 or 20 years. However, in the current economicenvironment, the conventional approach to road maintenance is to fix themost often travelled pavement first, and then repair, as budgets allow,progressively the better pavement, such that a useful life closer to 12or 13 years is typically observed.

SUMMARY OF THE INVENTION

A method for repairing asphalt pavement is desirable that is bothinexpensive when compared to conventional techniques, while yielding apaving surface having an equally long or longer useful life whencompared to asphalt pavement repaired by conventional techniques. Amethod is also provided for rejuvenating aged asphalt so as to bring itspaving properties closer to that of virgin pavement.

A composition and method for repairing pavement, that exhibits animproved lifespan when compared to conventional methods is desirable.Such a composition can result in improved binding between the asphaltand rock. Such a composition can also impart improved resistance tomechanical stress and shearing (e.g., from rolling loads that operate atan angle of incidence). The compositions are configured to modulate thefailure mechanisms of the pavement, so as to impart improvedwaterproofing, maintenance of microtexture, maintenance of macrotexture,resistance to embrittlement, resistance to delamination, and resistanceto mechanical stress. These improved properties greatly extend thelifetime of the pavement beyond that which would be observed for aconventional new pavement or a conventional repair method on existingpavement.

DESCRIPTION OF THE DRAWINGS

FIG. 1A provides a top view of an apparatus for applying aggregate andreactive emulsion to paving surface to be repaired, the apparatusincluding 5.7-8 tubeless tires (2400 lbs/ea) 102, a 2 HP SCR DC motor108, a ½ HP DC 20:1 motor 104, and a 1:1 chain drive 106.

FIG. 1B provides a side and front view of the apparatus of FIG. 1A. Anairpot adhesive tank is not depicted. Electric power and compressed aircan be provided to the apparatus by a support unit, not depicted. Thehopper is loaded with a heated aggregate, and the apparatus isconfigured to move at a speed of 20 feet per minute, with a maximumspeed of delivery of aggregate of 75 feet per second. The apparatusincludes: 3/16×4″×6″ box tubing 110; a 7″ dia. stone accelerator wheelhousing 112; a 3″ dia. oscillating stone accelerator tube 303/304 SS114; an adjustable heated screed knife and plate assembly 303/304 SS116; a 6″ hopper screw ASM 118; and a 0.4 C.Y. hopper 12GA 303/304 SS120.

FIG. 2 provides a schematic view of a HALO emitter of one embodimentemployed in the SPARC-HALO system to cure a SPARC elastomer over adamaged pavement in a SPARC-HALO elastomer/emitter sequence 200. Theemitter includes an AC power source 202 and a HALO emitter panel 3-15W/in² (power density) 204 and emits radiation of a variable wavelength:mid IR—terahertz 206. The radiation is applied to SPARC elastomer withvarying concentrations of aggregate (Δ) and wavesplitting particles (˜)208. Radiation of variable wavelength: long IR—terahertz 210 passesthrough to an old pavement cross section 214 having dry weld treateddefects therein 212.

FIG. 3A provides a schematic view of a portable HALO device, FIG. 3Bprovides detail of the interior of an emitter panel module of theportable HALO device, and FIG. 3C provides detail of the emitter panel.The HALO device is powered by a 200 KVA Tier IV Gen-Set 302. The deviceincludes an array of ˜4′×4′ modules 314 of adjustable height 312 (framenot shown). Each module includes (8) 12″×24″ emitter panels 306 permodule, emitting 1000-400 Watts/panel. The array is 96 S.F. and emits192000 Watts of radiation. Electrical connection(s) 304 from the emitterpanel to control panel and generator are provided. The emitter panelincludes a metal shell 306, rigid ceramic insulation 308, and anembedded emitter panel 310. The emitter is a panel 310 comprising aserpentine wire 311 and a birefringent micaceous material 312 throughwhich the electromagnetic radiation generated by the emitter passes

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following description and examples illustrate a preferred embodimentof the present invention in detail. Those of skill in the art willrecognize that there are numerous variations and modifications of thisinvention that are encompassed by its scope. Accordingly, thedescription of a preferred embodiment should not be deemed to limit thescope of the present invention.

Contrary to conventional methods, the SPARC-HALO system paving repairmethods not only repair the pavement to a uniform surface with pavingproperties similar or superior to conventional asphalt paving, but alsochange the character of the underlying deteriorated road bed to minimizeor eliminate the telegraphing of cracks. This character of theunderlying pavement is a function of, e.g., the starting composition ofthe road, how the road was initially manufactured, exposure of the roadto ambient conditions and different loads over time, and prior repairprocesses.

Dry Aggregate Preparation Stage

The initial stage in the SPARC-HALO pavement repair system involves apreparatory stage where deviations from a uniform surface plane (e.g.,potholes, divots, cracks, grooves, compressions, ruts, and the like) inthe pavement are filled and compacted with select gradations of dryaggregate. These deviations can penetrate deep into the surface of arough pavement, typically to a depth of up to 3 or 4 inches. Theaggregate serves to infill lost volume to the structure and return thepavement surface to a uniform plane, with no divots, ruts, or othersizeable irregularities. The aggregate is also selected to exhibit theproper combination of micro and macro texture to ensure good tractionfor vehicles traveling over the road under ambient conditions. Typicalaggregate size ranges from ¼ inches in diameter to ⅜ inches in diameter;however, smaller or larger aggregate can be employed. Suitable aggregateincludes coarse particulate material typically used in construction,such as sand, gravel, crushed stone, slag, recycled concrete or asphaltpavements, ground tire rubber, and geosynthetic aggregates. In pavingapplications, the aggregate serves as reinforcement to add strength tothe overall composite material. Aggregates are also used as basematerial under roads. In other words, aggregates are used as a stablefoundation or road/rail base with predictable, uniform properties (e.g.to help prevent differential settling under the road or building), or asa low-cost extender that binds with more expensive cement or asphalt toform concrete. The American Society for Testing and Materials publishesa listing of specifications for various construction aggregate products,which, by their individual design, are suitable for specificconstruction purposes. These products include specific types of coarseand fine aggregate designed for such uses as additives to asphalt andconcrete mixes, as well as other construction uses. State transportationdepartments further refine aggregate material specifications in order totailor aggregate use to the needs and available supply in theirparticular locations. Sources of aggregates can be grouped into threemain categories: those derived from mining of mineral aggregatedeposits, including sand, gravel, and stone; those derived from of wasteslag from the manufacture of iron and steel; and those derived byrecycling of concrete, which is itself chiefly manufactured from mineralaggregates. The largest-volume of recycled material used as constructionaggregate is blast furnace and steel furnace slag. Blast furnace slag iseither air-cooled (slow cooling in the open) or granulated (formed byquenching molten slag in water to form sand-sized glass-like particles).If the granulated blast furnace slag accesses free lime duringhydration, it develops strong hydraulic cementitious properties and canpartly substitute for Portland cement in concrete. Steel furnace slag isalso air-cooled. Glass aggregate, a mix of colors crushed to a smallsize, is substituted for many construction and utility projects in placeof pea gravel or crushed rock. Aggregates themselves can be recycled asaggregates. Many polymer-based geosynthetic aggregates are also madefrom recycled materials. Any solid material exhibiting propertiessimilar to those of the above-described aggregates may be employed asaggregate in the SPARC process.

Once the dry aggregate is placed in the damaged areas (potholes, largedivots, large cracks, or compressions), it is preferably compacted,smoothed and leveled off.

It is generally preferred to remove road reflectors and thermoplasticimprinting and safety devices (crosswalk markings, etc.) by mechanicallyremoving, e.g., scraping off, prior to placing the aggregate. However,an advantage of the SPARC-HALO system over conventional processes isthat there is no need to clean the pavement beyond broom clean, e.g., byremoving dirt, nor is there a need to remove paint.

Reactive Emulsion Stage

In the second stage of the SPARC-HALO process, a reactive asphaltemulsion which is hot is sprayed, poured, or otherwise applied onto thedry aggregate-filled surface. The reactive asphalt emulsion thus appliedquickly penetrates into small cracks and crevices in the old pavement aswell as dry aggregate-filled areas, providing a substantially fullysaturated cross section to a surface of the plane of the road. Becauseof the high penetrating ability of the reactive asphalt emulsion, only asmall amount of binder is needed to form a strong bond with the dryaggregate—typically approximately 10% binder to 90% dry aggregate. Thereactive hot emulsion is typically applied in the form of a 20% solidemulsion in water. The water in the reactive asphalt emulsion eitherflashes off during subsequent activities, or is absorbed by theaggregate or otherwise remains in the paving system. The binder bondsnot only the new aggregate together, but also new aggregate to oldpavement, and old pavement together.

The SPARC-HALO method utilizes various combinations of elastomers andother components so as to achieve a road surface exhibiting an extremelygood toughness, extremely good stretchability, good environmentalresistance, and good adhesion. The compositions are waterborne,sprayable, and can be provided as a single package. A plurality ofcrosslinkable binder elements is employed. In addition to binding newaggregate and aged pavement, the reactive emulsion compositions may beconfigured for use as a primer/tack coat, a stress absorbing interlayer,or a texture restoring and waterproofing top coat.

The compositions exhibit viscosities suitable for processing usingconventional paving techniques, and polymerize at a temperaturecompatible with conventional asphalt paving temperatures. Dissolvingdiluents and plasticizers are employed in conjunction with theelastomers such that the rubberized mixture of elastomer and asphalt isrendered into liquid form at room temperature, which yields tremendousadvantages in terms of handleability and ease of installation inaddition to long term performance of the resulting paving material. TheSPARC elastomer compositions include butyl rubber, diene modifiedasphalt, and environmentally hardened bioresins (bioresins that havebeen taken through a reactor cycle to enhance long term stability, sunresistance, and long term hydrolytic resistance), and containsnegligible to zero perfluorocarbons (PFCs), e.g., less than 1% PFCs asthe volatile components.

Alternatively to and in conjunction with the placement of dry aggregatein voids as previously described, the SPARC elastomer compositions canbe prepared as an ambient liquid that, at the job site, may be sprayedinto a mixer with aggregate. The composition coats the stone usingsimilar techniques as in a hot mix plant, except that it is done atambient temperature. The coated aggregate is laid on the ground andspread with conventional drag boxes or paving machines at a very thincoating. Depending upon the size of the aggregate, a thickness of 1/10inch can be obtained (e.g., using spray coating or other depositiontechniques); however, thicknesses of approximately ½ inch are typicallyemployed with using aggregate having a diameter of approximately ⅜inches. In certain embodiments, a polypropylene mat as describedelsewhere herein can be applied over the aggregate; however, in manyembodiments acceptable or excellent results can be obtained withoutusing such a mat.

The reactive emulsion is a waterborne emulsion of a polymer modifiedasphalt. The asphalt itself can be provided in emulsion form. Asphalt,also referred to as bitumen, is a sticky, black and highly viscousliquid or semi-solid that is present in most crude petroleums and insome natural deposits. Asphalt is used as a glue or binder mixed withaggregate particles to create asphalt pavement. The terms “asphalt” and“bitumen” are often used interchangeably to mean both natural andmanufactured forms of the substance. Asphalt is the refined residue fromthe distillation process of selected crude oils and boils at 525° F.Naturally occurring asphalt is sometimes referred to as “crude bitumen.”Asphalt is composed primarily of a mixture of highly condensedpolycyclic aromatic hydrocarbons; it is most commonly modeled as acolloid. Most natural asphalts contain sulfur and several heavy metalssuch as nickel, vanadium, lead, chromium, mercury, arsenic, selenium,and other toxic elements.

A number of technologies allow asphalt to be mixed at temperatures muchlower than its boiling point. These involve mixing the asphalt withpetroleum solvents to form “cutbacks” with reduced melting point ormixtures with water to turn the asphalt into an emulsion. Asphaltemulsions contain up to 70% asphalt and typically less than 1.5%chemical additives. There are two main types of emulsions with differentaffinity for aggregates, cationic and anionic.

Asphalt can also be made from non-petroleum based renewable resourcessuch as sugar, molasses, rice, corn, and potato starches, or from wastematerial by fractional distillation of used motor oils.

The asphalt can be modified by the addition of polymers, e.g., naturalrubber or synthetic thermoplastic rubbers. Styrene butadiene styrene andstyrene ethylenebutadiene styrene are thermoplastic rubbers. EthyleneVinyl Acetate (EVA) is a thermoplastic polymer. The most common grade ofEVA for asphalt modification in pavement is the classification 150/19 (amelt flow index of 150 and a vinyl acetate content of 19%). The polymersoftens at high temp, and then solidifies upon cooling. Typically,approximately 5% by weight of the polymeric additive is added to theasphalt. Rubberized asphalt is particularly suited for use in certainembodiments.

Functionalized triglyceride bioresins can be employed as the thermosetcomponent. Thermosets harden at high temperature. When employed incombination with a thermoplastic component, the composition maintainsits shape better on heating and under high temperature conditions.Suitable bioresins are derived from triglycerides—fatty acid triestersof the trihydroxy alcohol glycerol. Triglycerides are an abundantrenewable resource primarily derived from natural plant or animal oilsthat contain esterified mono- to poly-unsaturated fatty acid sidechains. They can be obtained from a variety of plant sources, e.g.,linseed oil, castor oil, soybean oil. Linseed oil comprises an averageof 53% linolenic acid, 18% oleic acid, 15% linoleic acid, 6% palmiticacid, and 6% stearic acid. Cross-linking can occurs at points ofunsaturation on the fatty acid side chains. The triglycerides can bemodified to contain epoxy and/or hydroxy groups by methods known in theart to improve cross-linking and to allow the triglyceride to becross-linked using conventional urethane crosslinking chemistries.

Suitable binder crosslink components include resins that aremultifunctional and react with active hydrogens, e.g., in carboxylic orcarbonyl, or hydroxyl. These resins can include bisphenol A-based liquidepoxy resins and aliphatic glycol epoxy resins as marketed by The DowChemical Company, polyurethanes, and isocyanates. The binder crosslinkcomponent is water dispersible but will stay buffered from going into acrosslink in the presence of water. Upon evaporation of the water, itwill self-cross within 24 hours just from UV initiation. As long aswater is present in the mix, the components can remain in proximitywithout cross-linking (e.g., yielding a single component formulation).

Suitable suspension components include pre-crosslinked bioresinsuspension gels. They react with both the crosslink component andcatalyst to yield a tough, water resistant, shear resistant plastic. Thesuspension component is preferably relatively inexpensive, hastremendous robustness, and is not hydrophobic.

Suitable catalysts include multi-functional pre-dispersed initiators(MFXI). Multifunctional initiators are those that possess more than onefunctional group capable of providing a site for chain growth. Thecatalyst assists in improving growth of molecular weight, and whencompounded into the polymer imparts robustness. The catalyst can beactivated by either ultraviolet radiation (e.g., sunlight) or heat.Suitable multifunctional catalysts can include one or more sulfates anda reactive metal that is an electron scavenger, which can causecrosslinking between a hydrogen-seeking crosslinking agent and otherfunctional groups in the presence of water.

The components of the reactive emulsion composition can undergo athermotropic conversion, resulting in entanglement and/or bridging atfunctional groups such that the resulting reaction product comprisesboth thermoplastic and thermoset elements. The resulting compositionexhibits a superior suspension (the “yield”) against the settling of themuch denser inorganic element (fine to coarse aggregate) by theformation of a “clathrate” or “cage-like” medium. This fully integrated,interlocking connectivity between the three polymeric componentsmaintains the aggregate in place and better protected from the elementsthan in conventional formulations.

The thermoplastic component and the thermoset/suspending componentspossess chain-terminating functional groups that are hindered mostly bywater but will selectively react to form a crosslink, upon waterevaporation, to the thermoplastic functionality rather than to thefunctionality of sister thermoset molecules, thereby forming a truethermotrope rather than a less precise molecularly entanglement whichexhibits more amorphous (and less useful) physical properties. Thecomposition can be provided as a single package, which isactivated/cross-linked upon removal of the water. The chain chemistry issuch that thermoplastic moieties are coupled to thermoset moieties. Whenheated, it will act like a thermoplastic but it will have substantialresistance to distortion because of the thermoset components. Therelative amounts of thermoplastic and thermoset components willdetermine the resistance. For example, a small amount of thermoplasticmoieties with a large amount of thermoset moieties will exhibit littleplasticity upon heating. The resulting cross-linked material can beconsidered to be a thermotrope that will behave like both a thermosetand a thermoplastic at different temperatures.

The thermoplastic component in the water-borne compositions of selectedembodiments is a preferably a polymer modified asphalt emulsion, withthe polymer typically a styrene, ethylene, butadiene styrene, or astyrene butadiene styrene polymer. The midblock, e.g., butadiene and/orethylene butadiene, can be linear or radial. Polyethylene glycols, suchas those available from Kraton and Asahi, are water-soluble nonionicoxygen-containing high-molecular ethylene oxide polymers having twoterminal hydroxyl groups. They are available in a broad range ofmolecular weight grades, and include crystalline thermoplastic polymers(MW>2000) suitable for use in certain compositions of the variousembodiments. An additional broad range of properties is available byintegrating polyisobutylene rubber (e.g., Oppanol® manufactured by BASFof Ludwigshafen am Rhein, Germany). The Oppanol® polyisobutylenes are ofmedium and high molecular weight, ranging from 10,000 MW up to 5,000,000MW. The following are properties of commercially available Oppanol®polyisobutylenes that are suitable for use in SPARC elastomercompositions of preferred embodiments.

Viscosity in Average molec- solution (isooc- Stau- ular weight, Stabi-tane, 20° C.) dinger viscosity lized Concentration Index (J0) average(Mv) [with Oppanol ® [g/cm3] [cm3/g] [g/mol] BHT]medium-molecular-weight Oppanol ® B 10 SFN 0.01 27.5-31.2 40 000 No B 10N 0.01 27.5-31.2 40 000 Yes B 11 SFN 0.01 32.5-36.0 49 000 No B 12 SFN0.01 34.5-39.0 55 000 No B 12 N 0.01 34.5-39.0 55 000 Yes B 13 SFN 0.0139.0-43.0 65 000 No B 14 SFN 0.01 42.5-46.4 73 000 No B 14 N 0.0142.5-46.4 73 000 Yes B 15 SFN 0.01 45.9-51.6 85 000 No B 15 N 0.0145.9-51.6 85 000 Yes high-molecular-weight Oppanol ® B 30 SF 0.00576.5-93.5 200 000  No B 50 0.002 113-143 400 000  Yes B 50 SF 0.002113-143 400 000  No B 80 0.002 178-236 800 000  Yes B 100 0.002 241-2941 110 000   Yes B 150 0.001 416-479 2 600 000   Yes B 200 0.001 551-6614 000 000   Yes

The reactive emulsion can be sprayed or poured on a prepared orunprepared pavement surface to be repaired. Upon contact with hot rock,the water present evaporates and the composition sets. Once set, thecomposition may be compacted by a vibrating roller while at or above150° F. The resulting surface has a very low void density, a highresistance to heating and softening, and it has anchor points with awearing core essentially that is bound into it that will not move if newpavement is placed on top. The compositions of preferred embodimentsenable the densification to be dramatically improved, e.g., 5% voids canbe reduced to 2-2.5% voids. The life of the pavement is increasedsubstantially upon improvement in densification.

Although dry, untreated aggregate can be employed in the preparatorystage, in certain embodiments it can be desirable to pretreat theaggregate surface to form “anchor points” by coating with a waterdispersible thermoset resin that has, in addition to the functionalgroups which selectively couple with the thermoplastic functionalitydiscussed above, an independent, mid-morphology, pendulous functionalitywhich bonds with a sufficiently improved strength to the specific rockchemistry being used in the final composition. This helps assure thatthe film stays in place and does not prematurely slip laterally. Abenefit in an application such as an interlayer primer is much highercompaction and thus a lower void density, i.e., improved resistance tooxidative, hydrocarbon embrittlement and ultimately a noticeably longeruseful.

The reactive emulsions exhibit superior properties when compared toconventional formulations. The superior properties can be in the areasof handling, storability, hazmat, curing characteristics, environmentalconsiderations, chemical resistance, water resistance, sun resistance,tensile and flexural quanta, and anti-strip quanta. The compositions canbe handled, stored and installed using conventional equipment. They canexhibit reduced hot mix asphalt (HMA) concrete void density. They canprovide a novel way to restore microtexture to a pavement surface. Theycan exhibit improved water resistance and/or sun resistance. Thecompositions can provide the highest mechanical properties versus unitof cost, and are sustainable. The compositions reform and stabilize abroad range of weakness in asphalt and result in a substantially lowerlife cycle cost of pavement maintenance.

Elastomer Coated Aggregate Stage

In certain embodiments, after the aggregate has been placed and thereactive emulsion has been applied, optionally a thin layer (from about⅛ inches or less to about 1 inches or more) of elastomer coatedaggregate is either sprayed or spread across the surface of the pavementso as to provide a uniform surface and to fill in any other depressionsthat were not aggregate filled during the dry aggregate preparationstage.

Heating Stage

After the dry aggregate preparation and reactive emulsion steps, thepavement can be considered a “wet” system that, if left to slow cure,would eventually provide some degree of quality as to the drivingsurface. However, the heating step subsequently employed in theSPARC-HALO system results in a dramatically superior driving surface.The heating element applies microwave-infrared radiation that penetratesdeep into the pavement, softening it and crosslinking the upper portionsof new material, yielding a material that after compression into a densestructure will exhibit properties well exceeding those of conventionalasphalt pavement in terms of toughness, resilience, flexibility, and/orresistance to cracks. In the lower, old pavement portions beneath thenew portions the heating and rolling process compresses and pushestogether the warmed old asphalt and the preparation of the nearlyvolatile-free: emulsion or the SPARC emulsion, eliminating voids, tocreate a tougher and more durable transition region between the oldpavement substrate and the new overlay. The transition region is acontinuum, and at depths of from 2½ to 3 inches or more, past which thepreparation or SPARC emulsions and/or the electromagnetic energy do notpenetrate. The material is essentially old asphalt paving that has beenremelted and pushed together. Because it does not contain SPARCelastomer, the properties will be similar to those of conventionalasphalt; however, cracks and fissures will have been eliminated by theprocess and thus will not telegraph to the surface.

Accordingly, after application of the reactive emulsion (and optionallythe thin layer of elastomer coated aggregate aggregate) over theaggregate filled pavement surface, a heat shuttle including a heatingelement is passed over the pavement surface. The heat shuttle can be ofany suitable dimension, e.g., as large as or larger than 32 feet wide by32 feet long, or smaller, e.g., 8 feet wide by 8 feet long, or 4 feetwide by 4 feet long. In a particular preferred embodiment, the shuttleis sufficiently wide so as to cover an entire width of a standard roador highway traffic lane including associated shoulder, or a full widthof a typical two lane road. The heat shuttle is pulled across the top ofthe prepared surface. As the heat shuttle passes over the surface, aheating element delivers electromagnetic radiation having a frequency inthe terahertz to the mid-infrared range that penetrates through thelayer of elastomer coated aggregate, and down into the aggregate-fillednew portions as well as the undisturbed old portions of the pavementbeing repaired. The electromagnetic radiation having a frequency in themicrowave-infrared range penetrates down to a depth of 3 or more inches,heating the entire penetrated mass of repaired pavement to a temperatureof at least about 200° F., but preferably not more than 275-300° F.,yielding a softened heated mass comprising the topmost 3 inches of thepavement surface. An advantage of the SPARC-HALO system is that the oldpavement is not disrupted as part of the repair process, such that thereis minimal oxidation of the old pavement upon application of heat, suchthat minimal smoke is generated by the process.

The heat shuttle can incorporate various different types of heatingelements (also referred to as emitters, HALO emitters, or the like). Oneconventional type of emitter comprises a stainless steel tube whereinnatural gas or liquid propane gas are mixed with air and ignited,generating heat (infrared energy) that is released through the stainlesssteel tube. Although other types of alloys can also be employed for thetube, stainless steel is generally preferred for its slow deteriorationand for the bandwidth of energy that radiates from the outside of thattube typically in the medium to far infrared which exhibits goodpenetration into asphalt pavement systems. Other types of emittersinclude those incorporating a rigid ceramic element where the combustiontakes place in micropores in the ceramic element. Bandwidth for suchemitters is also in the medium to far infrared. Another type of emitterincorporates a flexible cloth-like ceramic medium having several layers,or layers of stainless steel cloth together with ceramic cloth. Thecloth traps the combustion gases so that no flame is present on thesurface of the element while generating infrared emissions. Any suitabledevice capable of generating infrared radiation that penetrates to adepth of 2, 3, 4 or more inches into the pavement surface can beemployed.

A particularly preferred heat shuttle incorporates a proprietary ceramicstructure in a form of thin sheets of cloth-like material that canoperate at much higher temperatures (e.g., 2000° C.) than conventionalceramics (e.g., 1500° C.). In this structure, a higher combustiontemperature can be obtained by catalyzing combustion of an air/liquefiedpetroleum gas (LPG) mixture or air/nitric gas mixture. The infraredelectromagnetic radiation generated is typically of shorter wavelengththan the previously described systems, and can more quickly andefficiently heat the pavement than these conventional systems. Thesystem also avoids creation of an open flame, with the resultinggeneration of smoke and other carbon emissions from the heated pavement.Any combustible mixture that slows down the combustion reaction suchthat longer wavelengths (as are characteristic for electromagneticradiation having a frequency in the terahertz range) are produced can beemployed to generate penetrating electromagnetic radiation. One exampleis methanol in LPG. Conventional combustion systems typically generateelectromagnetic radiation with a wavelength of from 1-5 nm. Instead, itis generally preferred that electromagnetic radiation of longerwavelengths, e.g., of from 2-5 mm (characteristic for electromagneticradiation having a frequency in the terahertz range) be generated.

In certain embodiments, simplified electronics and software can beemployed in connection with a HALO device that employs a simple emitter,so as to avoid high capital expenditures. The emitter is designed toproduce radiation at a wavelength or range of wavelengths that willpenetrate the pavement while at the same time minimizing excess heatingin an upper region of the pavement, such that substantially uniformheating throughout the asphalt medium down to a depth of at least 2inches is obtained. In some embodiments, substantially uniform heatingincludes a temperature differential throughout a preselected depth,e.g., 2 inches, of no more than 50° F. In other words, the temperatureof any portion of the upper region is no more than 50° F. higher thanany portion of the lowest region. However, in certain embodiments,larger temperature differentials may be acceptable, e.g., up to 100° F.or more, provided that damage to the cured surface is avoided.

To attain the desired temperature profile, radiation in the infraredregion is applied. The radiated energy applied to the surface isselected so as to control a depth of penetration and a rate ofpenetration to avoid heating or activating the asphalt too quickly,which may damage the pavement. The HALO devices of preferred embodimentscan be manufactured to minimize cost and are suitable for use in thefield. Field use can be achieved by powering the HALO device using aportable generator, e.g., a Tier 4 diesel engine, which qualifies undercurrent emission standards. In one embodiment, the generator iselectrically connected to a series of emitter panels situated within ametal frame. The device can be insulated with a high-density ceramic,and the panels can be nested within the ceramic liner of a frame pointsto point downward towards the pavement. One example of a HALO emitterpanel is provided in FIG. 2.

An array of panels can be assembled together, as in an array of 2×1panels, or any other desired configuration, e.g., 2×2, 2×3, 2×4, 2×5,2×6, 2×7, 2×8, 2×9, 2×10, 2×11, 2×12, 2×13, 2×14, 2×15, 2×16, 2×17,2×18, 2×19, 2×20, 2×(more than 20), 3×3, 3×4, 3×5, 3×6, 3×7, 3×8, 3×9,3×10, 3×11, 3×12, 3×13, 3×14, 3×15, 3×16, 3×17, 3×18, 3×19, 3×20,3×(more than 20), 4×4, 4×5, 4×6, 4×7, 4×8, 4×9, 4×10, 4×11, 4×12, 4×13,4×14, 4×15, 4×16, 4×17, 4×18, 4×19, 4×20, 4×(more than 20), 5×5, 5×6,5×7, 5×8, 5×9, 5×10, 5×11, 5×12, 5×13, 5×14, 5×15, 5×16, 5×17, 5×18,5×19, 5×20, 5×(more than 20), 6×6, 6×7, 6×8, 6×9, 6×10, 6×11, 6×12,6×13, 6×14, 6×15, 6×16, 6×17, 6×18, 6×19, 6×20, 6×(more than 20), 7×7,7×8, 7×9, 7×10, 7×11, 7×12, 7×13, 7×14, 7×15, 7×16, 7×17, 7×18, 7×19,7×20, 7×(more than 20), 8×8, 8×9, 8×10, 8×11, 8×12, 8×13, 8×14, 8×15,8×16, 8×17, 8×18, 8×19, 8×20, 8×(more than 20), 9×9, 9×10, 9×11, 9×12,9×13, 9×14, 9×15, 9×16, 9×17, 9×18, 9×19, 9×20, 9×(more than 20), 10×10,10×11, 10×12, 10×13, 10×14, 10×15, 10×16, 10×17, 10×18, 10×19, 10×20,10×(more than 20), 11×11, 11×12, 11×13, 11×14, 11×15, 11×16, 11×17,11×18, 11×19, 11×20, 11×(more than 20), 12×12, 12×13, 12×14, 12×15,12×16, 12×17, 12×18, 12×19, 12×20, 12×(more than 20), 13×13, 13×14,13×15, 13×16, 13×17, 13×18, 13×19, 13×20, 13×(more than 20), 14×14,14×15, 14×16, 14×17, 14×18, 14×19, 14×20, 14×(more than 20), 15×15,15×16, 15×17, 15×18, 15×19, 15×20, 15×(more than 20), 16×16, 16×17,16×18, 16×19, 16×20, 16×(more than 20), 17×17, 17×18, 17×19, 17×20,17×(more than 20), 18×18, 18×19, 18×20, 18×(more than 20), 19×19, 19×20,19×(more than 20), 20×20, 20×(more than 20), or (more than 20)×(morethan 20). The panels can be of any suitable size, e.g., 1×1 inches orsmaller, 3×3 inches, 6×6 inches, 12×12 inches, 18×18 inches, or 24×24inches or larger. The panels can be one or more of square, rectangular,triangular, hexagonal, or other shape. Preferably, the panels abut eachother so as to minimize non-emitting space; however, in certainembodiments some degree of spacing between panels may be acceptable,such that, e.g., circular emitters can be employed, or, e.g., squareemitters can be spaced apart. One example of a suitable array is a 2×12array of one foot square panels.

While in certain embodiments a coiled or straight wire can be employedin the emitter, in a particularly preferred embodiment the panelsinclude a serpentine wire as an emitter. An advantage of the serpentineconfiguration is that it does not have the high resistance exhibited byspaced apart coils. Accordingly, more of the energy is emitted asradiation of the desired wavelength. The coils are spaced apart tominimize the resistance, and a radiant energy is emitted within a“sandwiched” space bounded on the upper side of by the high-densityceramic that has a very low permittivity and essentially redirects thereflected energy from the serpentine wire downward.

On the lower side of the wires, which can advantageously be embedded ina support or be self-supporting, is a thin micaceous panel. The micagroup of sheet silicate (phyllosilicate) minerals includes severalclosely related materials having close to perfect basal cleavage. Allare monoclinic, with a tendency towards pseudohexagonal crystals, andare similar in chemical composition. The nearly perfect cleavage, whichis the most prominent characteristic of mica, is explained by thehexagonal sheet-like arrangement of its atoms. Mica or other materialsexhibiting micaceous properties can include a large number of layersthat create birefringence or trirefringence (biaxial birefringence).Birefringence is the optical property of a material having a refractiveindex that depends on the polarization and propagation direction oflight. These optically anisotropic materials are said to bebirefringent. The birefringence is often quantified by the maximumdifference in refractive index within the material. Birefringence isalso often used as a synonym for double refraction, the decomposition ofa ray of light into two rays when it passes through a birefringentmaterial. Crystals with anisotropic crystal structures are oftenbirefringent, as well as plastics under mechanical stress. Biaxialbirefringence describes an anisotropic material that has more than oneaxis of anisotropy. For such a material, the refractive index tensor n,will in general have three distinct eigenvalues that can be labeledn_(α), n_(β) and n_(γ). Both radiant and conductive energy from theserpentine wire is transmitted to the micaceous element. Thebirefringent characteristics of the micaceous material can be employedto transmit a subset of wavelengths generated by the serpentine wirewhile filtering out other wavelengths. The emitter of certain embodimentemploys a sheath of stainless steel that protects the micaceous materialfrom being damaged. This conductive sheath transfers energy with nosignificant wavelength translation. By employing this combination ofcomponents (e.g., serpentine wire, micaceous material, stainless steelsheath), energy generated by the serpentine wire with a peak wavelengthof about 2 micrometers can be taken down to about 20 micrometers. Awavelength of from about 20 to about 100 micrometers is generallypreferred for use in connection with asphalt applications. The thicknessor other characteristics of the micaceous material can be adjusted toprovide a targeted wavelength or range of wavelengths to the surface.

In a particularly preferred embodiment, the HALO device has a 2-footwide by 12-foot long intercavity dimension, configured similar to ahood, in which a ceramic insulation is mounted. The emitter elements areadvantageously 1 foot by 1 foot. E.g., a 2-foot wide HALO device can beconfigured to be 2 elements wide by 12 elements long, for a total of 24elements. Such elements can have a Watt density of roughly 14 Watts persquare inch, at full energy, capable of being powered by, e.g., agenerator that can deliver 250 kW. An example of a portable HALO devicesuitable for use in repairing asphalt pavement is depicted in FIG. 3.

A net frame is preferably attached to reels on the outside of thedevice, to permit adjustment of the emitter within the cavity itself, orto permit adjustment of the height of the emitter over the pavement. Ina preferred embodiment, the emitter is provided in a cavityapproximately 6 inches deep, and a height of the emitter surface overthe pavement surface can be varied from as low as a quarter of an inchor as high as an inch or more. The emitter is preferably placed as closeto the surface of the pavement as is practical (e.g., <1 inch, or <0.5inches, or <0.25 inches) so as to minimize loss of energy viareflectance and/or refraction by the pavement surface. However, if thespacing is too close, imperfections in the pavement surface, or smoke ordislodged gummy residue, may cause damage to the emitter.

In preferred embodiments for pavement repair applications, an emitterdesign can be employed wherein multiple units (e.g., 1, 2, 3, 4, 5, 6,7, 8, 9, or 10 or more) are grouped together. For example, four units,each including a 3×3 emitter array, will provide 36 square feet ofemitter. Four units, each including a 4×6 emitter array, will provide 96square feet of emitter. It is generally preferred to employ a squarefootage of emitter that can be supported by a desired generator. 250 kWgenerators are generally preferred, as providing a good balance of powerand cost, but in certain embodiments larger generators can be employed,e.g., a 300 kW generator. Instead of a larger generator, two or moresmaller generators can be employed to provide adequate power for apreferred array size. In a preferred embodiment, a 250 kw generator canbe employed to power a 100 square foot emitter array that puts out 14watts per square inch. Two such generators can be provided on the sametug to power 250 square feet of emitter. In most paving applications,the width of the road to be repaired is approximately 12 feet, soemitter arrays or groups of emitter arrays having a width of 12 feet anda sufficient length to provide an appropriate amount of energy to thesurface are desirable.

In operation, circuits and sensors can be employed to identify obstaclesunderneath the emitter unit, e.g., by sensing reflected energy or heatbuildup, and can adjust the power to the emitter or the distance of theemitter from the pavement surface. Other sensors can detect the presenceof combusted organics, e.g., a laser that can detect a certain amount ofsmoke passing through its beam. If high temperature is detected, theemitter can be distanced from the pavement, power can be reduced, or thespeed at which the emitter passes over the surface can be decreased.Similarly, if the temperature detected is too low, the power of theemitter can be increased, it can be distanced from the surface, or thespeed at which the emitter passes over the surface can be increased.

In certain embodiment, the heat shuttle passes over the pavement,flashing off non-VOC components and bringing moisture in the pavement tothe surface, warming the mass of pavement. The pavement is then allowedto cool down to a preferred temperature for compression, at which time avibrating roller is passed over the surface. An advantage of the systemis that virtually no smoke is produced while operating the system. Theresulting pavement has a density similar to new pavement, butincorporates durable elastomers imparting superior performanceproperties.

Another advantage of the SPARC-HALO system is that the SPARC elastomercomposition can be formulated to include a resealing adhesive that doesnot lose its internal cohesion (stickiness) over time. A road repairedusing the SPARC-HALO system that begins to show signs of wear(microfissures or cracks) can be readily repaired simply by passing theheat shuttle across the surface (for, e.g., 30 seconds to 2 or 3minutes), then passing a compaction roller over surface, which repairsand reseals the cracks. Should a crack appear in the pavement that isbeginning to show signs of wear, you simply pass the heat shuttle acrossthe surface. A quick pass of the HALO device of 30 seconds, followed bya roller pass, can result in a robust crack repair. Preferably, such aheating/rolling treatment is employed approximately every three to fiveyears so as to maintain the pavement in good condition for 20 years ormore.

Upon exposure to a temperature of approximately 250° C., the elastomerof the reactive emulsion crosslinks, generating a bond (between newaggregate, between new aggregate and old pavement, or between portionsof old pavement) of sufficient strength such that a conventional roadvibratory roller can be applied over the top of the pavement surface toprovide a new driving surface. During rolling, the vibratory compactionredensifies all the defects in the old road bed.

In some embodiments, additional elastomer can be applied prior tovibratory compaction. The elastomer is preferably applied as a spraythat penetrates into the old road surface, filling cracks and crevicessuch that when vibratory rolling takes place it further bonds the oldpavement together as well as regions between the new material and theold material.

Rubber, a material commonly employed in asphalt pavements, is a highenergy-absorbing material right on its surface. If it absorbs too muchenergy too quickly, it will become a source of combustion and can damagethe emitter unit or emit fumes into the atmosphere. Accordingly, in someembodiments it is desirable to include a feedback loop on each emitterpanel (e.g., a 1 foot square panel) in an array, so as to continuouslymonitor the power density at the emitter's particular setting and itseffect on the pavement. The power density can be, for example, 3 to 15W/in², corresponding to 0.47 to 2.33 W/cm² or from 133 to 664(ft·lb_(f)/min)/in². Each emitter panel can be independently operated soas to provide an appropriate amount of energy to the surface beneath.Because rubberized coating is commonly employed as crack sealer on oldroads, it can be desirable to have such control over each emitter panel.

To provide satisfactory pavement repair, the presence of irregularitiesand defects on the surface, such as cracks, fissures, low areas, and thelike, must be addressed. It is typically preferred to sweep off anythick cross-sections of dirt, to remove vegetation and to remove anyreflectors that are on the road. The presence of road paint, e.g., paintused for lane markers, generally does not present any issues as tooperation of the emitter, provided it is thin and does not containsubstances that may prevent uniform heating. The paint employed incrosswalks may contain substances that prevent uniform heating. In suchsituations, the crosswalk markings can be removed, the emitter can beoperated so as not to move over the markings, or the emitter is shut offwhen it goes over crosswalk markings (e.g., manually shut off, orautomatically shut off when markings are detected). Crosswalks thatcomprise a thick thermal plastic strip placed on the pavement caninhibit management of the delivery of energy into the deep pavement, andare desirably removed and reinstalled prior to pavement renovation, orsuch areas are avoided during renovation.

Irregularities and defects on the surface of the pavement can vary. Insome instances, the surface has a boney, or rough look and texture,where large rocks have essentially become islands rising above the lowersections of the pavement due to fine rock being dislodged. In someinstances, fissures or potholes that are in each up to two inches ormore deep may be present. Severe irregularities and defects can beadvantageously repaired using a combination of stone and a formulatedSPARC elastomer that glues the stone together once it's cured. The SPARCelastomer is applied to the surface and then cured using the HALOdevice. In certain embodiments, the coating can be as thin as one gallonor less per hundred square feet of stone and elastomer spread over thesurface, e.g., a coating as thin as a few thousandths of an inch. Incertain embodiments, a mixture of SPARC elastomer and aggregate can beblended to form a cold slurry that is spread over the surface to replacevolume on a damaged or deteriorated road and then cured using the HALOdevice. In such embodiments, an initial application of heat prior to theemitter can be applied, e.g., open flame or other heating unit asdescribed elsewhere herein, that causes an initial flashing of volatilematerials from the cold slurry. This initiates some degree of curing, toprevent adhesion of the slurry to the tires of the tow rig pulling theemitter. Alternatively, the tires, the driving unit and the HALO device,are configured so as to straddle the strip of pavement that is beingrepaired.

In the case of large and very long runs on highways, use of theSPARC-HALO system can minimize closure time, even under conditionswherein material is placed and compacted, due to the rapid curingobserved. In such embodiments, an uncured surface of various stone sizesand elastomer recipes can be spread across the surface and then the HALOdevice is pulled over it, simultaneously drying out and heating theadhesive on the surface while also, at a different wavelength, pushingenergy deep into the pavement so that, based upon the prescription forthe repair, simultaneous curing of the material on the top is achieved,along with and warming and disturbing to a homogenized state theinterstitial asphalt of the pavement up below to a depth of 3 inches ormore.

Following behind the HALO unit, a compactor can be employed once thepavement cools. Typical temperatures after HALO treatment are about 250°C. Once heat dissipates such that the temperature is 180-190° C., acompacting roller can be applied. A single or 2-drum roller withvibrating capabilities can be run across the surface to compact thevoids that are in the old pavement, basically reducing it to a densitythat is similar to that of virgin pavement, and further compacting thenew material down into voids and irregular surfaces of the pavementwhere the SPARC repair material had been placed. Multiple passes of aroller can be applied, e.g., two, three, four, or more passes. Three orfour passes will provide the density and the uniform fusion between theparticles that results in a long-lasting pavement cross-section.

The SPARC elastomer typically comprises four components, and is a veryrobust emulsion that can contain asphalts of various hardnesses. Theelastomer can also include butyl rubber, a styrene-butadiene-styrene(SBS) polymer, and a bioresin. The type of bioresins, the concentrationof the SBS polymer, and the molecular weight of the butyl rubberemployed, along with other components of the mixture, can be balanced toachieve a desired set of properties of the adhesive system in its curedform. The SPARC elastomer as desirably employed as a mask to protect theunderlying pavement as it goes through this heating cycle from oxidationat the surface, because the temperature is higher at the surface than itis deep down when the HALO system is applied to the pavement. In orderto have a sufficient amount of energy penetrating to depth so as tofluidize the asphalt, and to minimize hot spots, the SPARC elastomer canact as a mask to avoid oxidation of the asphalt where hot spots arepresent.

Depending upon the nature of the materials present in the SPARCelastomer, a wavelength separating effect can occur in the elastomer asin the micaceous material, such that certain wavelengths arepreferentially transmitted. The elastomer does not have to be a pureorganic material; it can have materials like silicon dioxide or othermaterials that have a desired permittivity to a particular wavelength,or birefringent or trirefringent properties. In some embodiments, thesecomponents are present in a volume as high as 50% in the SPARC elastomercomposition; however, in certain embodiments lower amounts can bedesirably employed, e.g., from 1-10% by volume, or from 10-50% byvolume.

The relative permittivity of a material under given conditions reflectsthe extent to which it concentrates electrostatic lines of flux. Intechnical terms, relative permittivity is the ratio of the amount ofelectrical energy stored in a material by an applied voltage relative tothat stored in a vacuum. For example, the power source can be theemitter, the transmitting device can be the medium through which theemitter's energy is passing, and the load is what actually happens whenthe molecular structure of the various substances adsorbs the energy.The movement of energy from the HALO device through the pavement mediumcan be described in terms of the relative permittivity of the pavement.For methodologies for creating a wavelength of energy, typicallyresistance wires are used for heating, e.g., wires comprising iron,aluminum, titanium, platinum, etc., and a variety of other materialsthat create design resistance. The resistance of the flow of electriccurrent creates infrared energy that falls in the bandwidth from amillimeter long down a few micrometers—the infrared (IR) microwaveboundary. Materials are heated depending upon the absorbent qualities ofpolar materials, like water, that they contain. There are certainbandwidths in the IR region that are highly condensed or captured withinthe structure of, e.g., water, and quick energy absorption is observed(e.g., a quick rise in terms of temperature as a result of that absorbedenergy). The IR microwave boundary can be considered that region betweenfar infrared and what can be considered extremely short microwaves(e.g., 1 millimeter). In preferred embodiments, it is desirable for theemitter to a substantial amount of energy in this region, e.g., 1, 5,10, 15, or 20 nm up to 1, 2 or more millimeters, preferably from about 2microns to 1 millimeter. Many materials are substantially transparent tomicrowaves having a bandwidth that is down in the megahertz andkilohertz range, which are very long bandwidths compared to IR heating.These microwaves penetrate materials readily that do not have a highhydroelectric constant or a high relative permittivity. The microwavetransmissivity of common materials such as are used in the pavingindustry or other industries are well known or readily ascertained byone of skill in the art. The refraction and reflection that takes placebetween the emitter surface and the surface of the SPARC emulsion whenit is placed on the top of the pavement can likewise be ascertained, soas to achieve a desired temperature profile in the pavement.

In an asphalt pavement surface contacted with energy having a 20micrometer wavelength against the surface, the presence or absence ofthe SPARC emulsion on the surface can have a profound affect in terms ofhow much energy is refracted, reflected and, transmitted below thesurface to the interstices of the asphalt at, e.g., three inches indepth. Refraction is the change in direction of a wave due to a changein its medium. It is essentially a surface phenomenon. Refraction ismainly in governance of the law of conservation of energy. Momentum dueto the change of medium results in the phase of the wave being changed,but its frequency remains constant. As energy moves from the emitter tothe surface of the pavement, the rate of movement remains the same, andthe wavelength remains the same; however, the incident wave is partiallyrefracted and partially reflected when it hits the surface. Snell's Law,also referred to as the Law of Refraction, is a formula that is used todescribe the relationship between the angles of incidence andrefraction. Refraction that takes place at interface, e.g., a boundarybetween air and a solid, can exhibit a phenomenon referred to as anevanescent wave, wherein the wavelengths on one side of the boundary arepartially reflected and partially refracted. At the boundary, reflectedenergy or wavelengths can come back from the substance, creating achaotic collision of electromagnetic energy that is generally one-thirdof the wavelength. For either a narrow energy source such as a laser ora broad infrared radiant energy source coming to the surface of a solid,one is able to measure this perturbance and predict with a degree ofaccuracy how much energy is returned and how much is transmitted, whichimpacts the amount of energy transmitted into the pavement. An advantageof the SPARC emulsion on the pavement surface is that it disrupts theorganized formation of a wave bouncing back out of the pavement, suchthat more energy can be transmitted into the pavement. Knowing thewavelength that is presented to the pavement, the evanescence wave thatis created, and the permittivity of the material enables one to predictand control the heating characteristics of the pavement. The relativepermittivity is an absolute number for stone, for water, for theatmosphere of the voids in the pavement, for the asphalt that is in theinterstices. When considered together, one can analyze what the effectof a particular wavelength on its rate of movement through the pavement,e.g., through the use of conventional probes for determining energylevels and bandwidth changes. This permits the emitter and the materialsemployed in the SPARC emulsion to be selected such that wavelength canbe manipulated to about a millimeter, which is in the terawatt range. Inthis range, the depth of penetration for the amount of energy that isused from the generator is profoundly improved, such that energyconsumption is reduced.

For an emitter temperature that is at 750° F., and for an immediatesurface temperature, e.g., ⅓ of the wavelength below the SPARC emulsionlayer that is 55°° F., within a few seconds, because it istime-dependent, a temperature at just below the surface, e.g., amillimeter below the surface, is 75°° F. Moving down progressively inincrements of ½ inch to one inch, the emitter temperature versus thesurface temperature versus the temperature at various depths can beanalyzed. This power depth loss of the energy as it enters the pavementfrom the irradiated surface can be compensated for by manipulating thesurface energy, the Watt density, the wavelength, the effects ofevanescence wavepaths, and the wavelength of energy passing through thepavement so as to increase the uniformity of heating from the surface toa desired depth (e.g., 3 inches). As top temperature threshold, it isdesirable to avoid the formation of organic gases, which indicates thatthe material has gone past the threshold of maintaining its originalmolecular structure. If gas formation is not apparent, as indicated bythe absence of smoke, the power can be increased; however, that is notthe only factor that should be considered. The other factor is a desireto minimize the amount of power that it takes to get the energy as deepas it needs to be (e.g., as can be determined by characterizing how deepthe voids are that are part of the flaws in the pavement so that it canbe determined how long the unit has to stay over a certain spot with aparticular configuration to reach that depth). One must also achieve atemperature such that when a roller is applied to the heated pavement,it is fluidized and will compress to eliminate voids, wherebyhomogenization of the rejuvenated pavement is achieved.

In terms of relative permittivity, that of water, for instance, is 80times higher than that of rock, which is 7. Asphalt's relativepermittivity is similar to that of water-60-70 times higher than that ofrock. Rock is can be considered substantially microwave transparent.This means 95% of the pavement cross-section is essentially transparentto millimeter wavelengths. Referring back to Snell's Law, the moreoblique the angle of the radiation coming to the surface from itsboundary zone (critical angle incidence), the higher the refraction andthe higher the reflection. The angle of incidence of the radiation cantherefore be manipulated to adjust the amount of energy transmitted.Okay. I had incoming calls, sometimes that botches my transmission. Themicrowave wavelength is going to interface a solid surface at a muchmore direct angle, such that for a microwave transparent material likestone, some IR energy that is quickly absorbed by the aggregate in theinterstices can be desirable for heating.

In preferred embodiments, it is desired to move energy from the emittersurface to 3 inches deep in the pavement, in the shortest amount of timewithout destroying or otherwise significantly damaging the materials inthe upper region. The SPARC-HALO system can enable this to be achieved.In contrast, heating with gas-fired, open-flamed propane that generatesprimarily IR radiation results in excess surface heating-smoke comingoff the pavement, indicated destruction of organic pavement constituentssuch as rubber or asphalt. The components' molecular weights can benegatively impacted, causing the damaged portions to lose waterresistance, adhesiveness, and other desirable properties. The SPARC-HALOsystem also results in reduced fuel costs, compared to conventionalcombustion systems, which are impractical to tune for wavelength byadjusting, e.g., air/fuel mixtures, and are extremely inefficient interms of power consumption per unit of energy transmitted to thepavement.

The composite structure of the pavement is 95% aggregate that exhibitsmicrowave transparency, whereas 75-78% of the remaining 5% is in theform of polar molecules that are affected dramatically by contact withmicrowave radiation. In use, the emitter is turned on and drawn acrossthe pavement. The entire continuum of the wavelengths and how energy ismoving through the pavement is in a state of flux, meaning that somewater molecules will be lost from the system. This changes the potentialfor an evanescence wave, as the polar structures that are in the SPARCemulsion are removed by evaporation, thus affecting the transmission ofenergy. In addition, energy is stored within the rock and theinterstices of the asphalt, which also changes the way that the energymoves through the substrate. It is therefore desirable to have a systemconfigured to monitor such conditions, and that can also utilizefeedback on how different Watt densities, different emitters, andchanges in the components that are employed in the SPARC emulsion canmaximize the use of the energy while minimizing potential damage to thepavement during homogenization of the interstices down to 3 inches indepth.

By analyzing data from experiments with different paving materials anddifferent SPARC emulsion compositions, emitters can be constructed thatwork well with conventional asphalt concrete pavements, and that consumeless than 20% of the power of heaters in conventional use for heatingpavement, or even less energy (e.g., 5%). Such conventional methodsinclude burning liquid propane gas using a ceramic blanket, or the moresophisticated open flame or catalyzed gas systems.

In one embodiment, the SPARC emulsion includes a birefringent ortrirefringent material, and is provided in the form of apre-manufactured film. The film is rolled over the surface of thepavement, e.g., from a spool, and then the HALO system is run over thetop, yielding a sealed surface. It is desirable to avoid driving toomuch energy into isolated spots in the pavement where the energy isabsorbed quickly, e.g., due to the higher permittivity of asphalt, wateror other organic material such as rubberized asphalt. This can changethe molecular structure of the elastomer (e.g., by basically pre-curingit—a negative consequence). The elastomer begins to melt and flow overthe surface of the asphalt, such that blowing off of water or othervolatiles is avoided. This results in a zero (defined by EPA as lessthan 1%) volatile organic carbon (VOC) repair process.

The SPARC-HALO systems typically generate about 0.1% VOC, which ishighly desirable from an environmental standpoint and superior to manyconventional processes which generate smoke and release large amounts ofVOC.

Rock or very fine aggregate can be coated with SPARC elastomer and theelastomer can be pre-cured. The rock, which serves as a carrier of theSPARC elastomer, can then be placed due to its dry, free-flowing nature.By pre-firing the SPARC elastomer on a stone, e.g., in a plant, one canminimize the amount of energy one has to use in the field. Such amixture would offer advantages over cold-mix asphalt in terms of ease ofhandling in the field. The material is pre-fired, taken to a jobsite,spread out, and then heated using the HALO system to yield a qualityasphalt concrete pavement surface.

Oligopolymerization

In some embodiments, the radiation emitted by the heat shuttle ismodulated to emit at least some radiation in the microwave region. Thisfocuses heat on the asphalt between aggregate instead of the aggregateitself, essentially preheating the asphalt. This efficiently warms anddisturbs the voids and interstices in the pavement withoutdehydrogenation of the asphalt. The process can also be employed topolymerize oligomers (approximately 2-150 repeating units) and otherbroken polymer chains in the aged asphalt, causing them to link intolonger chains whereby ductility is improved. This process can bereferred to as oligopolymerization, and can be utilized in a process ofhomogenization by liquid asphalt oligopolymerization (HALO). Core testsindicate that pavement thus treated is as much as 85% equivalent to thevirgin asphalt binder originally found in the pavement in terms of:compressive strength, flexural compressive strength, and shear strength,compared to mere heating without oligopolymerization. Infrared radiationtransitions to the microwave frequency at a wavelength of about 1millimeter. When the wavelength gets shorter than 1 millimeter, theradiation is considered far infrared. Accordingly, for inducingoligopolymerization it is preferred to employ radiation wavelengthsslightly longer than 1 millimeter.

The SPARC-HALO system is a noninvasive method of restoring the pavementto the highest possible physical properties, such that the asphaltexhibits characteristics similar to virgin asphalt (“rejuvenatedasphalt”).

While the disclosure has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive. Thedisclosure is not limited to the disclosed embodiments. Variations tothe disclosed embodiments can be understood and effected by thoseskilled in the art in practicing the claimed disclosure, from a study ofthe drawings, the disclosure and the appended claims.

All references cited herein are incorporated herein by reference intheir entirety. To the extent publications and patents or patentapplications incorporated by reference contradict the disclosurecontained in the specification, the specification is intended tosupersede and/or take precedence over any such contradictory material.

Unless otherwise defined, all terms (including technical and scientificterms) are to be given their ordinary and customary meaning to a personof ordinary skill in the art, and are not to be limited to a special orcustomized meaning unless expressly so defined herein. It should benoted that the use of particular terminology when describing certainfeatures or aspects of the disclosure should not be taken to imply thatthe terminology is being re-defined herein to be restricted to includeany specific characteristics of the features or aspects of thedisclosure with which that terminology is associated. Terms and phrasesused in this application, and variations thereof, especially in theappended claims, unless otherwise expressly stated, should be construedas open ended as opposed to limiting. As examples of the foregoing, theterm ‘including’ should be read to mean ‘including, without limitation,’‘including but not limited to,’ or the like; the term ‘comprising’ asused herein is synonymous with ‘including,’ ‘containing,’ or‘characterized by,’ and is inclusive or open-ended and does not excludeadditional, unrecited elements or method steps; the term ‘having’ shouldbe interpreted as ‘having at least;’ the term ‘includes’ should beinterpreted as ‘includes but is not limited to;’ the term ‘example’ isused to provide exemplary instances of the item in discussion, not anexhaustive or limiting list thereof; adjectives such as ‘known’,‘normal’, ‘standard’, and terms of similar meaning should not beconstrued as limiting the item described to a given time period or to anitem available as of a given time, but instead should be read toencompass known, normal, or standard technologies that may be availableor known now or at any time in the future; and use of terms like‘preferably,’ ‘preferred,’ ‘desired,’ or ‘desirable,’ and words ofsimilar meaning should not be understood as implying that certainfeatures are critical, essential, or even important to the structure orfunction of the invention, but instead as merely intended to highlightalternative or additional features that may or may not be utilized in aparticular embodiment of the invention. Likewise, a group of itemslinked with the conjunction ‘and’ should not be read as requiring thateach and every one of those items be present in the grouping, but rathershould be read as ‘and/or’ unless expressly stated otherwise. Similarly,a group of items linked with the conjunction ‘or’ should not be read asrequiring mutual exclusivity among that group, but rather should be readas ‘and/of’ unless expressly stated otherwise.

Where a range of values is provided, it is understood that the upper andlower limit, and each intervening value between the upper and lowerlimit of the range is encompassed within the embodiments.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity. The indefinite article “a” or “an” does not exclude aplurality. A single processor or other unit may fulfill the functions ofseveral items recited in the claims. The mere fact that certain measuresare recited in mutually different dependent claims does not indicatethat a combination of these measures cannot be used to advantage. Anyreference signs in the claims should not be construed as limiting thescope.

It will be further understood by those within the art that if a specificnumber of an introduced claim recitation is intended, such an intentwill be explicitly recited in the claim, and in the absence of suchrecitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to embodiments containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean at least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that virtually any disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.”

All numbers expressing quantities of ingredients, reaction conditions,and so forth used in the specification are to be understood as beingmodified in all instances by the term ‘about.’ Accordingly, unlessindicated to the contrary, the numerical parameters set forth herein areapproximations that may vary depending upon the desired propertiessought to be obtained. At the very least, and not as an attempt to limitthe application of the doctrine of equivalents to the scope of anyclaims in any application claiming priority to the present application,each numerical parameter should be construed in light of the number ofsignificant digits and ordinary rounding approaches.

Furthermore, although the foregoing has been described in some detail byway of illustrations and examples for purposes of clarity andunderstanding, it is apparent to those skilled in the art that certainchanges and modifications may be practiced. Therefore, the descriptionand examples should not be construed as limiting the scope of theinvention to the specific embodiments and examples described herein, butrather to also cover all modification and alternatives coming with thetrue scope and spirit of the invention.

What is claimed is:
 1. A method for repairing an asphalt pavement,comprising: passing an emitter over a surface of a damaged asphaltpavement comprising aged asphalt, wherein the emitter comprises abirefringent material through which electromagnetic radiation generatedby the emitter passes, wherein the emitter generates electromagneticradiation having a wavelength of from about 2 microns to 1 millimeter,the radiation penetrating into the pavement to a depth of at least 2inches, wherein a temperature differential throughout a top two inchesof pavement is 100° F. or less, wherein a highest temperature in the toptwo inches of pavement does not exceed 300° F., and wherein a minimumtemperature in the top two inches of pavement is at least 200° F.
 2. Themethod of claim 1, wherein the emitter produces electromagneticradiation with a power density of from 0.47 to 2.33 W/cm² or from 133 to664 (ft·lb_(f)/min)/in².
 3. The method of claim 1, further comprising,after passing an emitter over the surface of the damaged asphaltpavement, compacting the asphalt pavement, wherein a density of thecompacted asphalt pavement is similar to that of virgin asphaltpavement.
 4. The method of claim 1, wherein a wire is positioned betweenthe high-density ceramic liner and the sheet of the micaceous material.5. The method of claim 4, wherein the wire is embedded in a support. 6.The method of claim 4, wherein the wire is self-supporting.
 7. Themethod of claim 4, wherein the wire is configured to emitelectromagnetic radiation with a peak wavelength of about 2 micrometers,and wherein the wavelength is lengthened to 20 micrometers upon passingthrough the micaceous material.
 8. The method of claim 4, wherein thewire is in a form selected from the group consisting of straight,coiled, and serpentine.
 9. The method of claim 1, wherein thebirefringent material is a biaxial birefringent material.
 10. The methodof claim 1, wherein a temperature differential throughout a top twoinches of pavement is 50° F. or less.
 11. The method of claim 1, whereinthe radiation penetrating into the pavement to a depth of at least threeinches, wherein a highest temperature in the top three inches ofpavement does not exceed 275° F., and wherein a minimum temperature inthe top three inches of pavement is at least 200° F.
 12. The method ofclaim 1, wherein each emitter panel comprises a frame having a ceramicliner, wherein the birefringent material is a sheet of a micaceousmaterial exhibiting biaxial birefringence.
 13. The method of claim 12,wherein the emitter comprises a hood having a cavity therein, whereinthe frame is attached to reels on the outside of the hood, to permitadjustment of the at least one emitter panel within the cavity.
 14. Themethod of claim 13, wherein the emitter panel is configured to beadjusted such that a distance of an emitter surface to a pavementsurface is from a quarter of an inch to an inch.
 15. The method of claim12, wherein the emitter further comprises a power source configured tosupply electrical power to the at least one emitter panel, wherein thepower source is a portable generator.
 16. The method of claim 15,wherein the portable generator is a diesel generator configured todeliver at least 250 kW.
 17. The method of claim 12, wherein the damagedasphalt pavement is a standard road or highway traffic lane including anassociated shoulder, and wherein the emitter is sized so as to irradiatethe standard road or highway traffic lane including an associatedshoulder.
 18. The method of claim 12, wherein the damaged asphaltpavement is a two lane road, and wherein the emitter is sized so as toirradiate a full width of the two lane road.
 19. The method of claim 12,wherein the emitter comprises a plurality of emitter panels, whereineach emitter panel is in a shape of a square or a rectangle havingdimensions of about 12 inches by about 24 inches, and wherein theplurality of emitter panels are arranged in an array wherein eachemitter panel abuts an adjacent emitter panel.
 20. The method of claim12, wherein the emitter comprises a 2×12 array of one foot squareemitter panels.
 21. The method of claim 12, wherein the emitter furthercomprises a tow rig configured to pull the emitter unit.
 22. The methodof claim 12, wherein the emitter further comprises a sheath of stainlesssteel configured to protect the micaceous material from being damaged.23. The method of claim 12, wherein the emitter panel is configured toemit electromagnetic radiation at a wavelength of from about 2 micronsto about 100 microns.
 24. The method of claim 12, wherein the emitterpanel is configured to emit electromagnetic radiation at a wavelength offrom about 20 microns to about 100 microns.